Intensive behavioral weight loss programs are effective in helping people achieve the clinical recommendation of 5-10% weight loss, although efforts to disseminate less expensive and time consuming programs have found reduced effectiveness. Stress appears to be a critical factor impacting weight loss and maintenance, but although stress may be mentioned in weight loss programs, specific stress management skills and strategies for weight loss are not typically emphasized. The present project proposes to integrate mindfulness-based stress management into an existing employer-sponsored telephone counseling and internet-based weight loss program with the goal of improving outcomes. Project hypotheses are that the integration of mindfulness-based stress management with a behavioral weight loss program will increase the effectiveness of the program for those participants reporting high levels of stress-related eating. Content of the intervention includes a mind/body treatment rationale and direct and experiential mindfulness and mindful eating instruction with the goal of decreasing perceived stress and the associated overeating that accompanies it. During the two year project funding period, the investigators will develop the intervention and evaluate the feasibility and efficacy of the intervention by conducting a preliminary randomized trial. This trial will compare the integrated stress and weight loss treatment to weight loss treatment as usual in 183 overweight and obese individuals. Primary outcomes will include internal disinhibition (eating in response to emotion or thoughts), eating self-efficacy, perceived stress and weight lost at 6 months.